Genetic Syndromes with Associated Immunodeficiencies

Several genetic syndromes that feature prominent non-immune system problems can be associated with immunodeficiency. These disorders are sometimes collectively referred to as “syndromic primary immunodeficiencies” (PIDs) or “syndromic immunodeficiencies.” The immunodeficiency component of these disorders ranges from mild to life-threatening and can be highly variable even within the same disorder. Syndromic immunodeficiencies can be caused by known single-gene defects or complex chromosomal abnormalities, and the cause of disease may also be unknown. This chapter presents two representative cases to illustrate the complexity of syndromic primary immunodeficiencies and discusses general considerations.